1. Field of the Invention
The present invention relates to a light intercepting frame of a lens and more precisely, it relates to a light intercepting frame which intercepts harmful light (luminous flux) which causes ghost or flare or the like.
2. Description of Related Art
A photographing lens unit in a presently available camera is compact but complicated in order to increase the zoom power (magnification), resulting in a complex internal construction of the lens barrel. Light incident on the lens barrel is reflected by lens surfaces, lens ends, internal surfaces of the lens barrel or other internal components in the lens barrel. The internal reflection causes ghost or flare or the like which damages the picture.
An image plane is defined by an aperture which is usually provided in the vicinity of a film plane, so that harmful light which does not define the image plane is intercepted by the aperture.
However, such harmful light (luminous flux) can not be completely eliminated by the aperture, particularly in a zoom lens in which a terminal lens moves during zooming.
Furthermore, the shape of the picture plane of the film is rectangular, whereas the photographing lens has a circular cross sectional shape. Accordingly, light incident through the upper and lower edges of the photographing lens contains harmful components (luminous flux) which do not define the image plane, resulting in a production of ghost or flare etc.